Engine



Sept. 24, 1940. A. G. M. MICHELL ENGINE Original Filed April 26, 1958 INVENTOR nu. "(id/d2 \w \m E Patented Sept. 24, 1940 PATENT OFFICE ENGINE Anthony George, Maldon Michell, Melbourne, Victoria, Australia Original application April 26, 1938, Serial No. 204,403. Divided and this application June 8, 1939, Serial No. 278,024. In Canada April 4,

Claims.

This invention relates to an engine of the crankless type, under which designation are included all engines having pistons reciprocating in cylinders which are arranged parallel to the power shaft actuated by said pistons.

According to the present invention, two pistons reciprocating in each cylinder actuate severally two crankless shafts which are positioned in axial alignment with each other and geared to a common countershafh the two shafts being thereby caused to rotate in synchronism. In the form hereinafter described and illustrated in the accompanying drawing, the engine is arranged to operate on the two-stroke cycle. When a plurality of cylinders is used, they are arranged in a circumferential series around the power shaft axis.

Two-stroke crankless engines having multiple cylinders with only a single power shaft are already known, having been described, e. g., in the present applicants Reissue Patent No. 17,- 273. By the new construction which is the subject of the present application several important advantages are realized. In particular, the possibilities of torsional vibrations of the long crankless shafts, having comparatively massive slants or swash-plates at each of their ends, according to the prior construction mentioned, are obviated; the total length (and consequent weight), 30 of the shafting is considerably diminished; the

difiiculty of aligning the bearings (usually 4 or more in number), on the older long shaft is removed, each divided shaft of the new construction requiring two bearings only; the mutual 35 phase-relationship of the two pistons of each pair is rendered easily adjustable by re-assembly in altered angular positions of the gear wheels on their shafts, and the parts of the engine are rendered more readily accessible and more easily assembled. This latter and other constructional advantages are hereinafter more fully explained. a

This application is a division of application Serial No. 204,403, filed April 26, 1938.

The drawing is a longitudinal view, partly in section, of an engine constructed according to the invention, the plane of the partial section passing through the axis of a cylinder of the engine, and also through the axes of the two aligned shafts and of the countershaft geared thereto.

The cylinder I l, shown in axial section in the drawing, contains two pistons I3, I3a which respectively actuate the shafts II, II a by means of the slipper bearings I5, I5a mounted in the crossheads I6, Ilia. of the two pistons, said slipper bearings engaging respectively with each of the two swash-plates or slants I2, I201. which are respectively attached to the shafts II, Ila and rotate therewith. The axes of the two shafts II, Ila are in one and the same straight line, the said shafts being rotatably mounted in pairs of journal bearings 20, 20a and H, 2Ia and respectively supported longitudinally by thrustbearings l8, IBa. The cylinder I4 is provided with exhaust ports 45 and scavenge ports 46, these ports being respectively opened and closed by the pistons I3 and I 3a in the manner usual in two-stroke engines. The scavenge air may be supplied by a fan 5i gear-driven from the shaft Ila, the delivery ports 52 of the fan casing 53 being connected to the scavenge air chamber 44 by suitable conduits or casings not shown. The exhaust ports 45 deliver into an exhaust chamber 42 and thence through ports M to the atmosphere.

A series of cylinders similar to the cylinder I4 and of any desired number and similarly fitted with pistons and members attached thereto, is arranged circumferentially around the common axis of theshafts II, Ila, one such cylinder It being shown in the upper part of the drawing. The two shafts II, Ila. are respectively geared by gear wheels 23, 23a to wheels '24, 24a fixed on the countershaft II], the said shafts being thereby caused to rotate at equal speeds. The slants I2, IZa consequently rotate in constant and approximately opposite mutual phase relationship, and the pistons I3, I3a reciprocate in approximately opposite phases in the cylinder I4. By suitable change of the angular mounting, of either of the gear wheels 23, 23a upon their respective shafts I I, Ila, or of either of the gear wheels 24, 24a on the shaft II], the phase relationships mentioned may be varied at will in the construction of several engines otherwise similar, or may be changed from time to time after construction of the engine for the purpose of adapting the engine to a particular speed, or other particular working condition affecting such relationship.

A number of similar engines, each consisting -of cylinders I4, pistons I3, I3a, shafts II, Ila, slants I2, I2a, bearings I5, I5a, I8, IBa, and other parts, as hereinafter described, may be arranged in a circumferential series around the countershaft I0, all being similarly geared thereto so as to form a composite power unit. A power unit of this kind is the subject of a United States patent application Serial No. 204,403, filed by the present applicant and of which this application is a division. The component engines may either be mounted in a casing 3i common to the whole, as shown in the drawing, or each engine may have an individual casing, the several casings being bolted or otherwise attached together so as to form a frame for the composite unit.

The outer bearing 53 or Elia and thrust bearing 38 or 3a of each shaft H or Ha are preferably mounted in a frame member 6! or 6541 preferably in the form of a spider detachable from the remainder of the engine casing as shown. By this means either of the shafts H or Ha together with the member 6i or 55a and the slant if or 2a, the slippers, crosshead and pistons engaging therewith may be inserted in or withdrawn from the engine in the axial direction independently of the assembly of the remainder of the parts of the engine. I The mounting of the slants l2, lta severally upon two relatively short shafts M, Ma instead of a single long slant shaft, as in engines of prior construction, has the further constructional advantage that space adjacent to the compression spaces at the middle of the lengths of the cylinders M, which in engines of prior construction is obstructed by the middle portions of the single long slant shaft, are available for the reception of fuel injectors, relief valves, indicator connections and similar fittings which are required to connect with the said compression spaces. Thus, in the drawing the fuel injector 38 of the so-called long reach type is inserted into the cylinder M adjacent to the countershaft ill in a line radial to the cylinder and intermediate between the inner ends of the shafts i l, i la. The existence of such space between the proximate or mutually adjacent ends of the said axially aligned shafts furthermore greatly facilitates the construction of the main casting of the engine, since it removes the necessity for carrying a housing surrounding the shaft through the exhaust and scavenge chambers 32 and N and water-cooling chambers 68.

The portions of the shafts i I and i la extending beyond the bearings Eli, 20a are formed with splines 62, 620.. In the end casings 34, 34a are mounted shafts 53, 63a. Sleeves 64-, Ma are rotatably supported at their outer ends on shafts 63, 63a and at their inner ends slidably engage splines 62, 62a. The gear wheels 23, 23a are mounted by splines on sleeves 6%, E la so as to be slidable thereon and the sleeves are provided with circumferential portions 65, 55a, engageably by suitable shifting means, not shown, by which the sleeves can be readily moved in an axial direction.

Although one specific embodiment of the invention has been particularly shown and described, it will be understood that the invention is capable of modification and that changes in the construction and in the arrangement of the various cooperating parts may be made without departing from the spirit and scope of the invention, as expressed in the following claims.

What I claim is:

1. An engine comprising a power cylinder, a pair of pistons reciprocating in opposite ends of said cylinder, 2. pair of rotatable engine shafts aligned on a common axis parallel to the axis of said cylinder and each actuated by one of said pistons, and gearing arranged to transmit motion from one of said shafts to the other so as to maintain them in a constant relative phase of rotation with each other.

2. An engine comprising a power cylinder, a pair of pistons reciprocating in said cylinder in approximately opposed phases, said cylinder having a compression space between said pistons, a pair of engine shafts aligned on a common axis parallel to the axis of said cylinder and having their proximate ends spaced apart in the axial direction, operative driving connections between each piston and one of said shafts whereby said shafts are rotated, a fuel injector arranged transversely between said proximate ends of said shafts and entering the said compression space of said cylinder, and a rotatable countershaft mounted parallel to said shafts and geared to each of them so as to synchronize their rotations.

3. An engine comprising a plurality of power cylinders arranged in a circumferential series with mutually parallel axes, a pair of pistons reciprocating in each of said cylinders, a pair of rotatable engine shafts aligned on a common axis parallel to the axis of said cylinders and each rotatably actuated by the pistons reciprocating in adjacent ends of said cylinders, and gearing arranged to transmit motion from one of said shafts to the other so as to maintain them in a constant relation of phase of rotation with each other.

l. An engine comprising a power cylinder, a pair of pistons reciprocating in said cylinder, a pair of engine shafts aligned on a common axis parallel to the axis of said cylinder, a member mounted on each of said shafts and engaging with bearing members carried by one of said pistons whereby said member and said shaft are rotated, and means for maintaining synchronism of rotation of said shafts, each said engine shaft being rotatably mounted in a member of the casing of said engine detachable from the remainder of said engine.

5. An engine comprising a rotatable power shaft actuated by pistons reciprocating in cylinders arranged parallel to said shaft and in a series extending circumferentially around it, a second power shaft rotatably mounted in axial alignment with the first said power shaft and actuated by pistons each reciprocating in approximately opposite phase to one of the first said pistons and in the opposite end of the cylinder containing such first said piston.

ANTHONY GEORGE MALDON MICHELL. 

